The FAA on Wednesday announced an Emergency Airworthiness Directive
on certain Precision Airmotive RSA-5 and RSA-10 fuel injection servos
to be inspected before further flight. Two recent incidents have been
blamed on a loose servo plug. According to the AD, the servo plug
gasket is thought to have shrunk with engine heat, which causes it to
lose torque against the servo housing. These plugs have been found
loose as well as completely separated from their threaded housings.
Loss of the plug could cause a lean condition.
The gasket part number is 365533, and has been used in new and
factory overhauled servos since August 22, 2006. This plug-and-gasket
combination is found in both the certified and Experimental-class
SilverHawk injection system. Pilots are urged to check the security
of the main hex by hand. If the hex moves at all, it is loose.
For more information, visit Precision Airmotive